There is a need for new sources of multipotent, highly therapeutically effective, patient-specific stem cells. The placenta is a novel potential source of fetal stem cells. Studies of therapeutic use involving placental stem cells have not been conducted. We plan to address this need by accomplishing a research program with support from the NIH that will enable us to develop a therapeutic product utilizing selected placental stromal cells for the treatment of Acute Lung Injury. Acute Lung Injury is a major cause of acute respiratory failure in critically ill patients which requires development of novel modes of therapy This project will further contribute to the advances in knowledge of stem cell function and to the potential for regenerative medicine using stem cells derived from the placenta. Our hypothesis is that the chorion of human placenta contains large numbers of mesenchymal stem cells, which release several beneficial paracrine factors. This hypothesis is based on our recent discoveries that human placenta is a hematopoietic organ and term placenta is a niche of abundant numbers of hematopoietic cells. Other cells, sharing the phenotype of stromal cells and embryonic cells are present in the mesenchyme of human placental chorion. These cells are highly active in paracrine signaling and secrete abundant quantities of growth factors like HGF, KGF, TGF-beta, FGF, GM-CSF, and angiopoietins. Stromal cells from the placenta are effective in restoration of barrier function of injured epithelial layers. In Specific Aim 1, we will test th multipotency of mesenchymal chorionic cells derived from human placenta and their high paracrine activity. We will generate chorionic mesenchymal cell lines and characterize their proliferation and differentiation potential. Cells will be characterized by their morphology, abiliy to propagate in culture, expression of markers of human embryonic stem cells (SSEA-3, Oct-4, TRA-1-60), and embryoid body formation. We will also measure the paracrine activity of cells by ELISA. Cells for therapy will be selected from 20 placentas upon the levels of secretion of HGF, FGF, TGF-beta, GM-CSF, and angiopoietins. In Specific Aim 2, we will test the potential therapeutic value of selected placental stromal stem cells for their efficacy in animal and human lung models of acute lung injury. Cells will be tested for treatment of mice with acute lung injury and for development of lung fibrosis. Placental cells will be further investigated for their effectiveness in facilitation of repair of injured lung epithelium and endothelium in an ex vivo perfused human lung preparation. This project will provide abundant, non-controversial and inexpensive source of therapeutically active stromal stem cells, available for use in humans within a very short period of time (2-4 years).